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DIY Stompboxes => Building your own stompbox => Topic started by: bioroids on December 13, 2003, 08:41:59 AM

Title: More switching
Post by: bioroids on December 13, 2003, 08:41:59 AM
Hi there

I'm building a pedal that switches between two guitars, and then switches between a tuner out and the regular (amp) out.

Is it a good idea to use the shunting to gnd way to turn off the unwanted signal? I'm asking this because otherwise the signal has to pass several 4053 switches, wich I dont like very much. But I dont have too much info on the shunt to ground technique.

Are there any articles on the subject, or anyona has any advice about this.

I thank you ahead.

Luck

Miguel
Title: More switching
Post by: bioroids on December 13, 2003, 09:08:59 AM
I found an earlier post by RG, so this is called "shunt muting". Now I have a term to do a google search.

Anyway any thought are apreciated

Thanks a lot

Miguel
Title: More switching
Post by: bioroids on December 13, 2003, 04:04:45 PM
Hi!

I couldnt find much on the subject on google, so I startd playing on the simulator and breadboard.

I made a circuit, It works, but I cant avoid the noise when I switch it off. Even using bigger caps, the sounds fades out (instead of muting abruptly) but in the middle of the fade it still makes a loud pump :evil: .

Can anyone help with this? The schem I'm using is at

http://ar.geocities.com/bioroids/shunt.htm

Thanks ahead.

Miguel
Title: More switching
Post by: Paul Marossy on December 14, 2003, 12:31:02 AM
Check out the wiring on this A/B box. I think it may help you figure that out...
http://www.fulltone.com/qaframe.html
Title: More switching
Post by: Nasse on December 14, 2003, 03:29:10 AM
I wish you have luck when you try to find good and simple electronic switching method. But seems that you are in the right way because you have breadboarded and tested your circuit. I believe there is a lot of info around about different methods. But finding it and getting it to work in real life is always not so easy.

I once did a switch/gate for line level signal by using cheap LDRs. Each channel had two resistors maybe 10-30 k in series in signal line, and two LDRs shunted to ground at the output side of the series resistors. So it was two voltage dividers in series. The resistors in series of signal line may add some noise and you may need some preamp and buffer here and there that adds noise and distortion and complexity, but it did not do it noticeably in my setup. And making matched stereo channels may be impossible.  But you could not hear any pops or clicks at switching on or off, and it was fast enough for that application.
Title: More switching
Post by: bioroids on December 14, 2003, 10:34:29 AM
Hi guys, I'll check this options. I liked the transistor circuit because I have too many of them, and they're pretty small.

I'm gonna test this a while more to see if I can make it work right.

Thanks again

Miguel